Process of manufacturing nitroglycerin explosives of reduced freezing-point.



UNITE STATES PATENT OFFICE.

OSCAR EMIL WALTER sroHRER, OF CHARLOTTENBURG, GERMANY.

PROCESS OF MANUFACTURltlG NIIROGLYCERIN EXPLOSIVES 0F REDUCED FREEZINGQPOINT.

Nasesaesea Specification of Letters Patent.

latented June 4, 1907.

Application filed AprilllO, 1906. Serial No- 610,997-

To all whom; it may concern.-

Be it known that I, OSCAR EMIL WALTER ,STfIHRER, a subject of Prussia, residing at Charlottenburg, Germany, have invented a new and useful Process of Manufacturing Nitroglycerin Explosives of Reduced Freezing-Point, of which the following is a specification.

This invention relates to a process of transforming glycerin into diglycerin by means of simply heating the glycerin without additions. To this purpose, it will be advantagleous to proceed as follows :-The glycerin is sated, under ordinary pressure and With, out any addition for some length of time until it boils vigorously (about 190 to 195 centigrade), there being used for this purpose a refrigerating condenser which allows the water formed during said process to distil over and the glycerin vapors to condense. If the heating operation is interrupted after 5 or 6 hours, there has formed in the viscous mass 65% .diglycerin which can be obtained by distilling under a pressure of 810 mm, between 245-250 centigrade as a ver viscous liquid which is clear as water, an which tastes like glycerin, very sweet and absorbs water readily in the atmosphere. Molecular Wei hts ascertained according to the method oi lowering the freezing point, were in accordance with the theory (166). If one part of the diglycerin isgraduallypoured into ten parts of a mixture of 13 parts of water, 58 parts of sulfuric acid and 29 parts of nitric acid, at a temperature of 10-15 degrees G., there will be obtained, after repeated washing with water, a viscous slightly'yellowcolored liquid which is insoluble in water, but readily soluble in the usual organic solvents for example ether, alcohol, acetone, benzol and chloroform. The uantity of nitrogen contained in this liquid, of which it has been found that it amounts to 15.98%, confirms the formula C,,I'I (NO,,) O. The molecular Weight was 331,-theory 346. The specific weight was 1.544.- When exposed during several days to a temperature of 20? (3., it does not show any inchnation to freeze. l/Vhen mixed with silicious sinter in proportion of 25 parts of silicious sinter to parts of tetranitrodi. glycerin and if shot in Trauzls lead block under the testing condition for guhr dynamite, there resulted an extension of 348 com. (nitroglycerin, if shot under the same con- 5 5 dition, effects an extension of 398 ccm.). It can be made to crystallize only with the greatest difliculty and it congeals with much more difiiculty than nitroglycerin and, if

ad ded to the latter, it acts in such a manner, oo that the latter, too, is rendered less congealable. A mixture of tetranitrodiglycerin and nitroglycerin in the proportion of 25 to 75 does not become frozen when exposed during a longer time at a temperature of -15 to 55- 2O centigrade.

Mixtures which are so diflicult to congeal can be obtained not only by means of adding tetranitrodiglycerin to nitroglycerin but also by meansfof nitrating a mixture of glycerin 7c and diglycerin which may be obtainedin the described manner, by means of heating glycerin. The method of making these mixtures is as followsz-Glycerin is heated under the conditions mentioned above and 75 kept boiling until a sample taken after fractionation invacuo shows a percentage of 75% glycerin and 25% diglycerin. This mixture is transformed into the nitrat-ed product in the same manner as above described for the pure diglycerin and this product purified by washing with water and a solution of sodium carbonate and stabilized. The resulting stufl is an explosive oil, which possesses regarding the nitroglycerin the advantages mentioned above and can be worked up in the same manner to explosivesand powders as nitroglycerin.

I claim The process of preparing a mixture of 0 tetranitrodiglycerin and trinitroglycerin consisting in heating. glycerin to its boiling point under normal atmospheric pressure, maintaining the mass at boiling temperature until it contains the desired percentage of diglycerin and nitrating the resultant mixture, substantially as described.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

OSCAR EMIL WALTER S'lllHRllR. Witnesses: r

HENRY HASPER, WOLDEMAR HAUPT. 

